Joseph wilson swan



To 'ALL 'wHoM IT MAY concerts:

JOSEPH WILSON SWAN OF NEWCASTLE-UPON-TYNE, ENGLAND. Letters Patent No. 61,368, dated January 22, 1867.

MODE -01" PRINTING PHOTOGRAPHS.

Be it known that I, Josarn WILSON Swnut'iif Ncwoastlcnpon-Tyne, England, have invented and made a certain new and useful Improvement in the Printing of Photographs; and Ido hereby declare the following to be a clear, and exact description of the same, and of the features'jvhich distinguish my improvement from the method of printing photographs heretofore employed. 7

I My invention-relates to that manner or style of photographic printing known as carbon or pigment printing. In this style ofprinting, carbon or other col'oring matter is fixed by the action of light, transmitted by a photographic negative, and receivedupon a surface composed of gelctine or other like substance, colored with carbon or other coloring matter, and made aensitivetolight by means of hichromate of potash, or bichromate of ammonia or other chemical substance having-like photographic property; those portions of the colored and sensitive gelatinous surface, whichare protected from the light, by the opaque or semi-opaque'portions of the negative, being afterwards washed awaybymeans of water, while the parts made insoluble by light remain and form a print. This kind of photogrnphioprinting, although possessing the advantage of permanency, and affording the means of insurexperienced in obtaining by it delicacy of detail and complete gradation of light and shade. The difficulties referred to were more particularly experienced in attempts to employ paper coated with colored gelatinous materials, and arose from the fact that, in order toobtain half-tone, certain portions of the colored coating,

lying behind or at the back of the actinically-impressed portions, require to be'washed away, and the employment of paper in the way ithas been employedhitherto, (not onlyas a means of supporting the colored coating, out also to form ultimately the basis or groiindivorlr of the printJobstructcd the romoval'of the inner or back portions of the colored coating and prevented the obtaining of a half-tone.

' Now, my invention consists in the formation, of tissues, adapted to the manner of printing referred to, and

composed of or prepared with colored gelatinous matter, and soconstructed that while they allow, inthe act of printing,.frce access of light to one surface of the colored gelatinous matter, they also allow free acccs of water and unobstructed removal of the non'afi'e cted portions act the colored matter from the opposite surface or back, in theact of developing; and I obtain thisresult either by the disuse of pap'er altogether, or by the use of it merely as a backing or temporarysupport of thc colorcd gelatinous matter, the paper so used becoming entirely detached from the colored gelatinousmatter in the act of developing, and forming no part of the ,print ultimately.

My invention consists, furthermore, in the special mode of using the said tissues, whereby superior halftone and definition-in the print are obtained, as aforesaid; and also of a mod 19f eifccting the rctransfcr of the in respect of right and left. i v r p Ip producing the photographic tissues referred to, I form a solution of 'elatinc; and for the purposc'of developed print from atemporary to a permanent basis, so as to obtain a correc tlbu in the position of the print imparting pliancy to the resultant tissue, I have found it advisable-to add to the gclatinc solution, sugar or other saccharine matter, or glycerine. To the said gelatinous solution I also add carbonaceous or other coloring matter, either in a fine state of division, such as is used in water-color painting, or in the state of a solution or dye, or partly in a fine state of division and partly in solution. With this colored gelatinous solution I form sheets or films, as hereafter described, and I render such sheets or films sensitive to light,- either at the time ofthcir formation, by introducing into the gelatinous compound bichromatc of ammonia, bichromatc of potash, or other photographic agent of like photographic property, or by applying to such sheets or films, after their formation in a non-sensitive state, a soliition of thc hichromat'e of potash, bic'hromate of ammonia, or: other substancc'of like photographic property. This latter method I adopt when thcshcets or films are not required for use immediately after formation. I I v v V I .will, in my future references to the bichr'omate of ammonia or the bichromatcof potash, or to other chemicals possessing analogous photographic properties, dcnorninate them the scnsitizcr, and in 1'f( rring to the colored gelatinous solution, I will denominate that mixture the-tissue compound, and Iwill describe tho sheet or film as tissue." y

When the tissue to be produced is required for immediate use I add the sensitiser to the tissue compound; but when the tissue is required to lie-preserved sometime before using, I prefer to omit the sc-nsitiser from the mg any required tone or color for the print, has not come into general use, because of the difiiculties hitherto form-allthe 'operationsavith the tissue compound, subsequent to the introduction of the sensitiser, suitably illumin'ated'pvith yellow or non actinic'light. Having prepared proceed to coat paper with it, or I form glass, I' att'ach to-the' coating :1; sheet of paper, "forthe purpose of stren' printingby means of ae'amera-obscura.

erase r 2' tissue compound, with a View to the tissue beingmnde sensitive to the light subsequently, by the application of a solution of the sonsitiser. i

' With respect to the composition of the tissue compounrhtit will be understood by chemists that it maybe varied, (without materially affecting the result,) by the addition or substitution of other organic matters similarly actcdupon by light, when combined with a salt-containing chromic acid such'as I have referred to. Such other organiomntters are gum-arabie, albumen, &c.; and one or more of these may be employed occasionally to modify the character of the tissue compound; but I generally prefer to'make it as followsi I dissolve, by the I aid of beau two parts of gelatino in'eight parts of Water, .and' to this solution I add one part of sugar and as I much coloring matter, in a finely divided state or in a state of solution, or both, as may be required for the production of a photographicprint with a proper gradation of light and shade. Where it is desired that the coloring matter of the print should consistentirely orchieily of carbon,I prefer to use lampblaek, finely ground and prepared as for water-color PQll'riiltf, or I use Indian ink; and where it is desired to modify the black, I

add other coloring matter to produce the color desiredj for instance, I obtain a purple black by adding to the cnrbn ultr: marine an d'Indian red. The quantity of coloring matter to be addedfto the tissue compound must be regulated by the nature of the coloring mutter employed, and also by thech'aru ctcr of the negative to be 'used in the printing operation. In preparing tissue to be used in printing \from negatives, technically known as t e k," I increase the p oportion of coloring matter relatively to .that of.the tissue compound, and I diminish -it for tissue to be used in printing from negatives of an opposite character. In making tissue which is sensitive from thcfirst, I udd to the tissuceompound, prepared as above described, more or less ofthe scnsi'tiser, varying the quantity added according to the nature of the sensitiser and to the degree of sensitivcness to be conferred on the tissue to be produced from it. For ordinary purposes, and where the tissue compound is made according to the formula before given, I add about'one part of a saturated solution of bichromate of ammonia to ten parts of the tissue compound, and. I make-this addition immediately previous to the preparation'of the tissue, and maintain the tissue compound in the fluidstateby'means of heat during the preparation of the tissue. In ordinary'cascs I maintain the solution at 90 Fahrenheit. I also'filter it through' finc muslin or flannel, and I peri in a place the tissue compound as described, I it into sheets upon plates of glass. In forming tissue upon glass, I prepare thoplates of glass with ox-gall or coat them with a film'of eollodion, so that the sheets of tissue, when dry, may be easily separated from the plates. I prefer to use plate" or patent platefglass. Having set. the uppersurface of the glass in a perfectly horizontal position, and warmed itl to about 90 Fahrenheit, I pour a quantity of the tissue compound upon it, (about two ounces to each square foot of gloss,) and I lead or spread it evenly over the entire surfaceby means of a glu ss rodh After allowing the coating to solidify, I placeit in a i box with eh-lorideof calcium or other desieeal'ting.substauceyor expose it to a current of dry air. When the coating isd'ry I remove it from the glass in a sheet, and use it in the manner hereinafter described. Where the tissue compound is applied over a coating of eollodion, the film produced by the collodion and that produced by the tissue, cohere,=and 'thetwo films form ouesheet. 'Sometimcs,.before the separation of the coating from the 'gthening the tissue and making it more easy to manipulate; In this case I apply the paper, in a wet state, to the dry gelatinous surface, and having attached the paper thereto in this manuerf-I allow itto dry and I then detach the film and adherent paper from thegloss, by'cuttiug-around the margin of the sheet and lifting it oil. .Where extreme smoothness of surface,

such as is produced by moulding the tissue upon glasses described, is not of importance, and where greater facility of operation is desired, apply; a thick coating of, the tissue compound to the surface of the sheet of paper. In this case the papcr is merely used as am' eans of formingand supporting temporarily the film produced from the tissue compound; and such paper SCPMaCGSffiOm the gelutinouscoating in a hubse'qucntstag'e of my process, 'I must here remark that it is only the tissue with a backing of paper that is adapted for sensitising ufterjt is made. i In coatings surfaceof pitperwiththe tissue compound,'I apply the sheet (sometimes of coin siderublb length and formed into a band) to the surface of the tissue compound,-contained in a troughand kept fluid bymeans of heat, and I draw orraise the sheet or length of paper 0d the surface with a regular motion, v and I sometimes apply mordtthan' one coating-to the same sheet in this manner.

coated paper where it will quickly dry, and if the sensitiser washdded to the tissue compound, I secludc After such coating I place the it'from injurioiislight, both during its preparation and whilst drying; The sensitive tissue prepared as above described is, when dry, ready receive an actinic impression, in the manner usual in photographic printing. I prefentquse'thc sensitive tissue within two duysqifterthc time of its preparation. When the sensitiser is omitted in' the preparation of the tissue it does not deteriorate by keeping. Therefore, when tissue is required which will-not deteriorate by long keeping, I omit the sensitiser from the tissue compound, and when this tissue is required for use I-render itsensitiv by immersion in a solution of the sensitiser; The scnsitiser that I prefer to use for this purpose is rim-aqueous solutioni of biehromate of potash, containing about nine per cent. of the bichromat'e After immersion in the above-mentioned solution, I place the tissue in a dcsiccating box,

or in a current-of dry air, and seclude it frominjurious light. 4 I

In applying to photographic printing the various modifications of the sensitive tissue,,prepa.rc'd as above described, I place the sensitive tissue upon a negative in an ordinary photographic printing frame, and expose to light in the manner usual in photographic printing, or I place it in a. camera-obscure, in the manner usual in When the tissue employed is coated withn film of collodionon one sido,, I place the collodionizecl side in contactwith' thenegative; or where it is used-in the camera, I place-the collodionizcd surface towards the light passing through "the camera lens? Where the tissue is not coated with collodion, and where paper forins one of the surfaces of the. tissue, the'othe'r surface being' formed of a co'atin g 3 arses 1 j or'llllm of. the tissue compound, I place the lastmamed surface in contact with the negative; or when using it in the camera, I present this surface towards the light transmitted byj the lens. After exposure for the requisite time, I take the tissuefrom the printing frame or camera, andmchntit inthe manner hereinafter described;

that is to say,.I cemont'theactinically-impressed surface downward upon a basis, (usually of pnper,) to serve 115 a support during ,the subsequent operation of developing, and sometimes with a view to the re-transier of the print to another surface after development. The surface on which it i's'to be mounted may be paper, card, glass,

-porce!ain, enamel, the. When the tissue has not been coated with coliodion previous to exposure to light, I

sometimes coat with oollodion before mounting for development. I omit the coating with co'llodion when a glossy snrfuce is notrcquirecl. In mounting the actinically-impresscd tissue on paper, (previous "to developmen't,).-in

the temporary manner, with a view to subsequent rc-transfcr to another eurface,.I employ a cement which is:

.ineoli'lblo in u'ater, ,hut'which can be dissolved by the application of asuitablesclvcnt, or that'posscsscs so muck tenacity that the paper or other support (attuchcd'temporarily to the tissue or paper by its means) l'nuy be subsequently detached without the use of a solvent. The cements that may housed for temporary mounting are very various; but I generally prefer to use a. solution of caoutchouc in benzole, consisting of about three parts of cuoutchouc and one hundred parts of benzolc. In using this-cement, I float the actiuically-impresscd surface ofthe tissue upon it, and I'trent in a'similur manner the paper or other surfuce intended to be used as the temporary basis of the print during development. After allowing the solvent to evaporate, I press the caoutchouc-coated surface oii-thc tissue and the caoutchouc-coated surface of the paper strongly together, in such a manner as to. cause them to coh'ere. When the actinically-impressed tissue is to be cemented to a surface that not only serves to support the print during development, but also permanently constitutes its basis, I prefer to use albumen. or a solution of gum-lac as the cementing material; and when I employalbumen, I coagulate or render it insoluble in water, (by means of heat, by alcohol, or by other mc ans,) after performing the cementin}; operation and previous, to development. Intho permanent, as in the temporary mode'of mounting, it is the actinically-imprcssedsurface of the tissuewhich is attached by the cement to the paper or other material required to constitute the basis of the print. Ai'tcr cementing the tissue, as described, I submit it to the action of water, sufficiently heated to cause the solution and removal of those portions of the colored gelatinous matter of the tissue which have not been rendered insoluhlcby the action of light during exposure in the printing frame or camera. Whore paperlias been used as a part of the original tissue, this paper soon becomes detached by the action of the ti-rm water, which then has free access to the under stratum or back of the colored gelatinous coating. The soluble portions of the tiss'ueboing removed by the water, the impression produced during -the exposure of the tissue in the printing frame or camera, becomes developed, and the picture remains adherent to the caoutchouc-coatcd paper or other basis to which the actinically-improssed surfacew-as cemented previous to development. 'I allow the water to act onthe prints during seireral'hours, so as todissolvc out the scnsitiser. I then remove the prints from the water ahd allow them to dry; and those not intended for re-transfer, but which have been permanently attached to paper previous to development, I finish by pressing and trimming in the usual manner. Those which have been mounted with caoutchouc, Ire-transfer topaper', card, or other surface. To effect the re-transfer, 1 coat the print, when dry, with a solution of gelatinel I prefer that the solution-should consist of about four parts of gelatinc, one part of glycerinc, and forty parts of water. I apply this, solution to the print by means of a brush, the temperature of the solution being about 100 Fahrenheit. When a print coated with this solution is dry, I place its surface in contact with a piece of paper or card to which'the re-trapsfor is to be effected, such piece of paper or card having been previou'slymoistencd with water, and I then press the print and moist paper strongly together by means of apress. By this means the gclatinized surface of the print is caused to adhere strongly to the moist paper or card, andthe print thus becomes enclosed between two papers. In this state I immerse it in a; solution of alum, and afterwards rinse it in water. I then suspendit to dry, and when thoroughly dry I rub benzole over pthe surface of the cnoutchouc-coatcd paper, which so diminishes the adhesion of the caoutchouc that the paper can be stripped off without injury to the print. This being done, the surface of the print becomes exposed, and it only remains to finish it by pressing, in the usual manner.

Having now set forth the nature of my invention of improvements in the 'printing of-photographs, and explained the manner of carrying the same into efi'ect, I wish it-to be understood that what I claim as my invention, and desire to secure by Letters Patent, is"

The method herein specified of printing photographs, consisting in- 1. The preparation and use of colored gelatinous tissues, substantially in the manner and for the purpose set fortln 2. The mounting of undeveloped prints, obtained by the use of colored gelatinous tissues, in the manner and for the purpose set forth.

' 3. The re-transfer of developed'prints, produced as above described, from a temporary to a'pcrmancnt basis.

In witness whereof I, the said Josnrn WILSON Swan, have hereunto set my signature.

- I JOSEPH WILSON SWAN.

In the presence of--- Joan Mnwson, Joe. Gannon. 

